Extension boom for derricks



' EXTENSION BOOM FOR DERRICKS Filed Feb. 7, 1929 VIII) VIII/III/I/IJIIIIIIII &

5 5mm ilmze; flwai'iiqy Patented Mar. 25, 1930 UNHTED stares; PATENT oFFicE Application filed February 7, 1929. Serial No. 338,101.

My present invention relates to extensible member 13 are pivoted at 14 to the lower porbooms,-and more particularly to an extension tion of the boom 15, such that the boom 15 boom for use in hoisting cargoes toand from may be raised or lowered on the pivot 14 or Vessels. the entire boom 15 swivelled about the mast Heretofore, in the loading and unloading by means of the swivel 11. '55

of ships in port, much valuable time has been At the outer end of the boom there is atwasted due to the fact that with the derricks tached the extensible boom inember 16 being and booms now in use for such purposes, provided at its outer end with a. collar 17 cargo handlers are unable to work full time rigidlyattached thereto, and having pivoted 10 on account of the tides. The booms now in thereon at 18 a supporting link member 19 use are one piece and after the tide has ebbed adapted to receive a pulley 20 pivoted therein for a certain period the boom will not reach at 21, a link 22 is also pivoted at 18 and adaptto handle the cargo, therefore, it is necessary ed to receive therein a pulley 23 the purpose to stop work and wait for the tide, which not of which is to provide means for attaching 15 only means a loss of time but also a resulting suitable block and tackle to raise and lower expense for everyone connected vwith theship. cargo.

' My present boom is designed to meet such The pulley 20 is associated with another shortcomings of the present equipment by bepulley located on the mast 10 and attached ing capable of extension and at the same time thereto by means of the strap member 25, be-

20 making possible the reaching of ordinarily ing pivoted to such mast 10 at 26, and by inaccessible places by swiveling on itself, means of cables 27 associated with pulleys 24 heretofore impossible with any solid piece and 20, the outer'end of the extensible boom boom. l member 16 is thereby provided with raising The principal object therefore, is an exand lowering means as well as a supporting 25 tensible derrick boom. l means when cargo is being handled on the Another object is an extensible boom capapulley 23. A secondary support means is 10- ble of being swivelled around on itself at apcated at the rear end of the extensible-boom proximately 90 degrees. member 16 in the form of a suitable eye-bolt Other objects and novel features compris- 28 associated with a pulley 29 also attached to 30 ing the construction and operation of my inthe top of the mast 10 and a cable 30 is provention will appear as the description of the vided therefor. V I apparatus progresses. At 31, there is provided a slidably mounted In the drawings lllustrating the preferred shackle, comprising an annular ring 32 proembodiment of my invention, vided with slots 33in which slides a spline 34 35 Fig. 1 shows a side elevation with the boom attached to either side of the boom member extended; 15. The upper portion of the shackle 31 is Fig. 2 is a section taken on the line 22 of composed of a bridge member 35 provided at Fig. 1 its top center with bearing 36 in which is'jour- Fig. 3 is a section taken on the line 3 3 of nalled a forked-pin member 37 the lower end 49 Fig. 1; and c V of which is threaded at 38 to receive a lock nut Fig. 4 is a sectiontaken on the line 44 of 39, which is held thereto by means of a trans- Fig. 2. I verse through pin 40. The nut 39 bears up In the drawings illustrating my preferred against a thrust washer 41 which is adapted embodiment of the device, 10 indicates a mast, to bear against the under side of the bearing 45 the lower end of which is provided with a 36. Theextreme lower end of the member 37 swivel member 11 shrunk about a groove prois rounded at 42 and seated in a cup shaped vided around the mast 10, the said swivel bearing43 found in the upper sideof'the band member 11 being a part of the fixture to which portion 32. the pulley 12 is attached by means of an offset The rear end of the extensible boom mem- 50 yoke member 13. The swivel 11 and yoke ber 16 is flatted 01f at 44 and adapted to fit between the two sides of the forked member 37, and a pivot member 46 is adapted to pass through the side members 45 and boom end 44 and be held in place thereto by means of a nut 47. i

A second slidable shackle 48 is pinned at 49 to the outer end of the boom member 15, the lower side of which is provided with an eyebolt 50, which carries a link 51 in which is pivoted a pulley 52 for use in raising or lowering cargo. gether at 53 and the two ends 54 and 55 are turned-over to form a part of a hinge through which pins 56 pass and engage with similar hinge members 57 and 58, located on the'bottom ends of two encircling members 5? and 58 adapted to encircle the extensible boom member 16 and slide thereon. Abutting members 59 and 60 are located on the upper ends of the encircling members 58" and .51 such that the member 59 passes between the members 60 located on member 57 and an elongated hole 61 is provided in both'the central member 59 and the two members 60, such that a pin 62 may be inserted to hold the members57 and 58 in place, as shown in Figsl and 3. i

An internal pulley 65 is pivoted at-66 in the boom member 15 over which runs acable 67 the front end of which is attached to the extensible boom member 16 by means of an eye-bolt 68, and the other end of the cable 67 is attached to a link 69 associated with a pulley 70. a

The rear en dot link 69 is attached to a cable 71 which passes around pulley 12and over pulley and thereby provide means for extending. the extensible boom member 16 into the position shown in Fig. 1, and during such movement of member 16 cables 30 and 2? are brought into use to provide the necessary slack. lVhere the extensible member 16 is slid in on member v15, the cable T1 is given slack and the cables 30 and 27 are taken up. If it is desired to reach some ordinarily inaccessible point the shackle pin 62'n1ay be removed, dropping the band members 5? and 58 as indicated in dotted lines in Fig. 3 and the boom member 16 turned around at an angle with boom 16 by means of the swivel yoke member 37 pivoting in the cup 42 on the boom member 15. The boom member 15 may be maintained at an angle with the boom member-15 by suitable guy cable attached to the member 16, as is customary in everyday practice with ordinary cargo booms.

Having thus described my invention, what I claim as new, is: r a i 1. In a hoisting derrick, including a mast,

an extensible boom comprising two main parts, the lower part being rotatably vertically movable about said mast and-provided with longitudinally disposed splines attached to either side thereof, a shackle fixed to the outer end of said ,boom and The shackle'48 is welded to-- gitudinally movable member and alongitudinally fixed member, a shackle removably and slidably associated with the extension member of said boom, one side" of which is solidly attached to the stationary portion of said boom, a second shackle pivotally at tached to the rear end of said movable member in a vertical plane and adapted to slide on said fixed member, said second shackle further adapted to swivel on itself in a substantially horizontal plane, and means for extending said movable member on said fixed member.

r 8. In a holstmg derrick, the combination of a mast, an extensible boom comprising two mainparts, the lower part being rotatably and verticallg movable about said mast and provided with longitudinally disposed splines attached to either side thereof, a shackle fixed to the outer end of said boom and adapted to slidably. encircle the extension boom located above it, said shackle adapted to be removed from said extension boom, a rear shackle member adapted to be attached to the rear end of said extension boom and pivotally attached thereto, said rear shackle being slida-bly mounted on said firstboomandadapted to cooperate with: said splines therein,,means for swivelling said extension boom on said first boom and means for sliding said extension boom on said first boom, substantially as shown and described.

In an extension boom comprising a. longitudinally movable member and a longitudinally fixed member, the combination of a shackle removably and slidably associated with themovable member of said boom, one side of which is solidly attached to the stationary portion of said boom, a second'shackle pivotally attached to the rear end of said extensible member in a vertical plane and adapted to slide on said fixed member, said 1120 second shackle further adapted to swivel on itself in a substantially horizontal plane and means for extending said movable member-on said fixed member. a

In witness'whereof, I hereby subscribe my name this 6th day of January, 1929. W

' ALBERT C. CRANDALL' 

